What is Generators: Definition and 299 Discussions

In electricity generation, a generator is a device that converts motive power (mechanical energy) into electrical power for use in an external circuit. Sources of mechanical energy include steam turbines, gas turbines, water turbines, internal combustion engines, wind turbines and even hand cranks. The first electromagnetic generator, the Faraday disk, was invented in 1831 by British scientist Michael Faraday. Generators provide nearly all of the power for electric power grids.
The reverse conversion of electrical energy into mechanical energy is done by an electric motor, and motors and generators have many similarities. Many motors can be mechanically driven to generate electricity; frequently they make acceptable manual generators.

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  1. EinsteinKreuz

    Exploring Neutron Beam Generation via Compact Neutron Generators

    DISCLAIMER: This thread is a repost of another thread in the Nuclear/Particle Physics forum since I cannot delete that thread but this forum is more appropriate since it is more of a question in Nuclear Engineering than in Nuclear Physical theory. So I have been reading about the operational...
  2. K

    Voltage Output from AC Generators with More Loops

    Hello, I don't understand how more loops in the AC generator create bigger voltage. I understand when we talk about magnetic flux how it happens (rate of change of surface that's penetrated by field lines), but there's also the explanation that says "if the magnetic field penetrates the paper...
  3. rcgldr

    Packet generators - are these possible?

    I know that there are packet sniffers, but I'm wondering if a computer is not behind a router (such as cable modem or dsl with external ip setups (usually for multiple external ip's, one for each computer), if a program made to generate and output packets could directly generate a packet with a...
  4. L

    Why Does Induced EMF Change in Generators but Not Moving Conductors?

    why does induced emf change in case of generators but remains constant in case of moving conductor?
  5. Math Amateur

    MHB Every submodule has at least one set of generators?

    In Paul Bland's book: Rings and Their Modules, we read the following text at the start of Section 2.2 Free Modules:https://www.physicsforums.com/attachments/3388In the above text we read: " ... ... Every submodule has at least one set of generators, namely the set N. ... " Now, I know that...
  6. C

    MHD Generators - What electrodes to use?

    Hi everyone, What type of electrodes should I use for an AC saltwater MHD generator? I need something that is efficient yet corrosive resistant. Thanks
  7. R

    MHB Finding subgroups and their generators of cyclic group

    List every generator of each subgroup of order 8 in \mathbb{Z}_{32}. I was told to use the following theorem: Let G be a cyclic group of order n and suppose that a\in G is a generator of the group. If b=a^k, then the order of b is n/d, where d=\text{gcd}(k,n). However, I am unsure how this...
  8. C

    Are Big Power Plant Generators Different than Small Generators?

    I'm curious to know whether these huge generators [700 MW, 2235 MW] are same in construction as small generators, except bigger frame, coils and magnets? Also they say Generator is Motor and vice versa. So does it mean those big generators can be used as Motor too? In reality is it wise to...
  9. M

    SU(2) operators to SU(N) generators for Heisenberg XXX

    A paper I'm reading says "Our starting point is the SU(N) generalization of the quantum Heisenberg model: H=-J\sum_{\langle i,j \rangle}H_{ij}=\frac{J}{N}\sum_{\langle i,j \rangle}\sum_{\alpha , \beta =1}^N J_{\beta}^{\alpha}(i)J_{\alpha}^{\beta}(j) The J_{\beta}^{\alpha} are the generators of...
  10. D

    Cyclic Group Generators <z10, +> Mod 10 group of additive integers

    So I take <z10, +> this to be the group Z10 = {0,1,2,3,4,5,6,7,8,9} Mod 10 group of additive integers and I worked out the group generators, I won't do all of them but here's an example : <3> gives {3,6,9,2,5,8,1,4,7,0} on the other hand <2> gives {2,4,6,8,0} and that's it! but...
  11. A

    Calculating Coil Windings in Generators

    hi , i want to know that how calculate coil windings in the genarators, i want make a small genarator with magnetic and copper coil for 12 volt but i couldn't find a formula for number of coil cycle please guide me about this , thank u.
  12. M

    Generators: Armature Lap & Wave Windings

    what is meant by parallel path in lap and wave windings of armature of an generator
  13. E

    Lorentz Generators in Light Cone Coordinates

    how can we write and interpret Lorentz generators in light cone coordinates?
  14. B

    Q3: How do we measure rotational degrees of freedom in quantum mechanics?

    I have a basic question that still is not clear to me. In QM, various operators are generators of something (ie. momentum is a generator of linear translations, Ang. Mom the generator of Rotations and such) Question 1: Let us look at L, or a component, say Lz. When we operate on a...
  15. O

    MHB What are Cyclic Subgroup Generators and How Do We Determine Them?

    i am having a difficulity understanding the concept of cyclic subgroup generators. may I be given an explanation with examples if possible of how you determine whether a function is a subgroup and when they say list all cyclic subgroups eg <Z_10,+>. show that Z_10 is generated by 2 and 5
  16. S

    Why do Van de Graaff generators produce such low current?

    I'm currently in a program to be a physics teacher and for an upcoming mock lesson plan I am going to show the scene from Jurassic Park where the kid gets blasted off the electric fence and talk about if it is realistic. To supplement my discussion I'll be using a Van de Graaff generator to...
  17. F

    Calculating Damping Coefficient of a Generator

    Hey, I understand that damper windings are used to stabilize the speed of the rotor under varying loads. The rotor speed is decreased or increased by the induction principle. Physically the damped windings are some sort of copper bars inserted into the pole faces of a rotor and all...
  18. A

    Van de graff generators maximum voltage

    Why do van de graff generators have a maximum voltage( charge on the sphere ) . Why can't they just accumulate charge on the sphere as large as we desire?
  19. T

    Vibration effect of Generators

    Hi, I am training to be a Building services engineer. I have come across a problem where I have to calculate the vibration from the generator and the transformer to the striation of the building.. how should I do it?
  20. S

    How Do Lorentz Group Generators Comply with Their Commutation Relations?

    The Lorentz group generators, in any representation, satisfy the commutation relation [S^{\mu \nu}, S^{\rho \sigma}] = i \left( g^{\nu \rho}S^{\mu \sigma} -g^{\mu \rho} S^{\nu \sigma} -g^{\nu \sigma}S^{\mu \rho} +g^{\mu \sigma} S^{\nu \rho} \right) and the Lorentz transformation is...
  21. V

    Electric Generators and Faraday's Law

    Homework Statement When a generator turns at 60 Hz, the amplitude of the induced EMF is 50 V. What is its amplitude when it turns at 180 Hz if the magnetic field remains the same? Homework Equations ω = 2∏f ε = ε0sin ωt The Attempt at a Solution If f = 180 Hz, ω = 2∏(180 Hz)...
  22. C

    Conserved quantities as symmetry generators

    Suppose we have a Lagrangian \mathcal{L(\phi, \partial_\mu \phi)} over a field \phi, and some variation on the field \delta \phi. If this variation induces a variation \delta \mathcal{L} = \partial_\mu F^\mu for some function F^\mu, then Noether's Theorem tells us that if we construct the...
  23. 1

    Photons, QFT and electric generators

    hi, friends. i am 15 and have made a device using electric motors and generators which is able to produce more "electrical output" than the "electrical input". i have won the national science fair with this but the problem is that the judges say i am braking the 2nd law of thermodynamics and...
  24. D

    Finding the elements of a group given two generators and relations

    Hey everyone Let's say I have two generators, a and b, with the following relations: a^{5}=b^{2}=E bab^{-1}=a^{-1}; Where E is the Identity element. What I've done so far is this - the number of elements of the group is the product of the exponents of both generators, which is 10...
  25. B

    Can pulse generators output 100mA?

    If I have a pulse generator what is the current it can output? It doesn't say in the datasheets IF I have a 5V pulse and 50ohm output impedence am I supposed to believe it outputs 100mA? And then if my load is 1ohm I should get something near 100mA through it?
  26. I

    Question on power plant generators

    I'm trying to understand exactly how power plant generators increase power output. So I will explain what I think is right. To increase the power output of a generator more torque from the prime mover is required to increase the torque angle between the voltage impressed on the stator from...
  27. D

    Proving that a set is a set of generators

    Homework Statement I want to show that the set $$ <1,x,x^2,\cdots ,x^n> $$ forms a basis of the space $$ P_{n} $$ where $$ P_{n} $$ contains all polynomial functions up to fixed degree n. The Attempt at a Solution I have already shown that the set $$ <1,x,x^2,\cdots ,x^n> $$ is linearly...
  28. P

    Generators - Voltage Sources or Current Sources?

    I am actually quite confused on how a generator is supposed to be modeled... To add more power to a bus, we put more generators in parallel at the same voltage (which is the bus voltage). Therefore, I would say generators are current sources as more generator are put in parallel, more current...
  29. B

    Does every permutation of group generators imply an automorphism?

    I couldn't find the words to summarize my question perfectly in the title so I will clarify my question here. Say we have a group G in which every element can be written in the form g_1^{e_1} g_2^{e_2}...g_n^{e_n}, 0 ≤ e_i < |g_i| . Suppose that there exists a different set g_1', g_2', ...
  30. B

    Large Scale Generators: Earth's Orbit & Electric Currents

    So, I was wondering if a conducting loop was placed in orbit around the Earth would it be able to generate a current?
  31. D

    Dedicated random number generators

    I was looking out for dedicated true random number generators and was surprised that there seem to be only very few around on the market. Anyone has experience here?
  32. V

    Calculating an expression for trace of generators of two Lie algebra

    Suppose we have $$[Q^a,Q^b]=if^c_{ab}Q^c$$ where Q's are generators of a Lie algebra associated a SU(N) group. So Q's are traceless. Also we have $$[P^a,P^b]=0$$ where P's are generators of a Lie algebra associated to an Abelian group. We have the following relation between these generators...
  33. Y

    Angular momentum operators as infinitesimal generators

    Hello everyone, I'm going through some lecture notes and there are some things I don't understand about the whole derivation of the angular momentum multiplet. It's said that the skew-symmetric 3x3 matrices J_i are the infinitesimal generators of the rotation group SO(3). Later, however...
  34. E

    Can Small Natural Energy Generators Efficiently Power Household Systems?

    I have a decent background in generators and my brother had an idea for building one he wants me to help him out. Without getting into specifics, it would be a natural energy generator integrated into his home electrical system. I have run into some issues though as i am more familiar with...
  35. U

    How exactly do generators work (Please explain the Faraday's law)

    Hi, everybody! I have done tons of research through the Internet, but still can't understand the Faraday's law and how a generator works. I understand, that inside coils, placed into a rotating magnet, current is generated. But why? What exactly happens to electrons, so they form current...
  36. N

    Understanding Electric Generators

    I think I am starting to understand various aspects of electrical generators, and I wanted to run this by the forum and have people correct my explanations, if needed. I understand there are many types of motors and this thought-experiment is just a permenant magnet near a coil. If anyone can...
  37. G

    Using generators to check for a normal subgroup

    Homework Statement Perhaps I should say first that this question stems from an attempt to show that in the group \langle x,y|x^7=y^3=1,yxy^{-1}=x^2 \rangle,\ \langle x \rangle is a normal subgroup. Let G be a group with a subgroup H . Let G be generated by A\subseteq G . Suppose...
  38. T

    Presentation of a group to generators in A(S)

    Is there a general algorithm for taking the presentation of a group and get the permutation generators for the subgroup of A(S) to which the group is isomorphic? For example, given x^5=y^4=e, xy=f(c^2) how do I find (12345) and (1243), the permutations corresponding to x and y? BTW, the example...
  39. D

    Are generators preserved under homomorphism?

    Sorry if this is such a basic question, but I'm not sure about the answer and having trouble finding it in my textbook. If I have a cyclic group G with generator g, and a homomorphism θ: G --> H, does this mean that θ(g) is a generator of H?
  40. L

    Proving Pauli Matrices are Generators of SU(2)

    I am confused with SU(2). How do you prove that the generators are pauli matrices (1/2 sigma)? I would appreciate any link or reference with details of all algebraic steps, taking one from the conditions of unitarity and det=1 to the well know exponential form. In general, how do you find...
  41. M

    Understanding Generators of Z6

    I understand how {1} and {5} are generators of Z6. {1} = {1, 2, 3, 4, 5, 0} = {0, 1, 2, 3, 4, 5} {5} = {5, 4, 3, 2, 1, 0} = {0, 1, 2, 3, 4, 5} But my book also says that {2, 3} also generates Z6 since 2 + 3 = 5 such as {2,3,4} and {3,4} I believe. Thus every subgroup containing 2 and 3 must...
  42. Einj

    Question about SO(N) group generators

    Hi all. I have a question about the properties of the generators of the SO(N) group. What kind of commutation relation they satisfy? Is it true that the generators λ are such that: $$\lambda^T=-\lambda$$ ?? Thank you very much
  43. R

    Infinitesimal generators of bridged stochastic process

    I hope someone can put me on the right track here. I need to derive the infinitesimal generator for a bridged gamma process and have come a bit stuck (its for a curve following stochastic control problem - don't ask). Any tips, papers, books that could guide me out of my hole would be greatly...
  44. B

    Question about electric generators

    Generators in power stations are usually connected to step-up transformers to boost their output voltages for long distance power transmission, but why not just use a generator that has been designed and built to produce really high voltages and just connect the generator directly to...
  45. L

    Lorentz Generators: (J and M) vs. S

    (if I am not even wrong, please let me know :smile:) The generators of the (proper-orthochronous) Lorentz transformations are usually denoted by {J_{\mu \nu }} or by {M_{\mu \nu }}. They consist of angular momentum generators and boost generators. When discussing spinors, the notation changes...
  46. T

    Generators and Coils vs Output Volts/Amps

    I know this is a bit of a newbie question but I want to learn something about generators. I want to build a simple hand cranked generator. Just a hobby. Making coils, and using magnets is the easy part but I don't understand the specifics around this. Can anyone tell me how to determine...
  47. C

    Find Cartan Subalgebra for Algebra Given Generators

    Hey! I am studying group theory for particle physicists right now and I came across the following general question (Tell me if you think this rather belongs to the homework section, I am new here.) Say I am given a set of matrices which represent the generators of an algebra, but I don't know...
  48. GreenAce92

    Space generators by temperature difference?

    This is another theoretical question post of mine. I read somewhere that there is a huge temperature polar opposite change in space just from shielding ie shadow vs. exposed to sun. That was because of the absence of an atmosphere or "stuff to keep the heat" So, pulling numbers from...
  49. J

    MHB Question about generators and relations.

    I am trying to use generators and relations here. Let M ≤ S_5 be the subgroup generated by two transpositions t_1= (12) and t_2= (34). Let N = {g ∈S_5| gMg^(-1) = M} be the normalizer of M in S_5. Describe N by generators and relations. Show that N is a semidirect product of two Abelian...
  50. L

    The meaning of the addition of the spin generator to the Lorentz generators

    When constructing the Lie algebra of the Lorentz Transformation, the references usually start with an infinitesimal proper-orthochronous transformation, and then find the infinitesimal generators. Let's call the set of these generators L. after finding L, the references usually compute the...
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